Garage conversion permits in San Diego County

The state law a San Diego garage conversion actually runs on

Garage conversions are governed by California's ADU and JADU law, Government Code §§66310-66342. They are not governed by SB 9, which is a separate lot-split and two-unit law at Government Code §65852.21. Attributing ADU rights to SB 9 is a common mistake and it leads homeowners down the wrong permit path.

The approval is ministerial. Government Code §66317 requires ADU applications to be "considered and approved ministerially without discretionary review or a hearing," and gives the agency 60 days from a completed application to approve or deny. If it does not, "the application shall be deemed approved." If the applicant asks for a delay, that 60-day period is tolled for the length of the delay. A denial has to come with a full set of comments listing what is defective or deficient and how the application can be fixed.

Read that clock carefully before budgeting around it. It runs from a COMPLETED application, not from the day drawings are first handed over the counter, and it is a deadline for the city's decision rather than a construction schedule. In the coastal zone, AB 462 extended the same 60-day deemed-approval structure to a completed coastal development permit application, effective October 10, 2025, subject to the exceptions in the statute.

Government Code §66323(a)(1) requires ministerial approval of an ADU created within the existing space of a single-family dwelling or an accessory structure, and the HCD ADU Handbook states plainly that "the conversion of detached garages, sheds, and other existing detached accessory structures into ADUs is permitted by State ADU Law." A detached garage is eligible. The question is which product it becomes.

Parking, owner-occupancy and the two rules people get wrong

Replacement parking is the first one. Government Code §66314(d)(11) reads: "When a garage, carport, covered parking structure, or uncovered parking space is demolished in conjunction with the construction of an accessory dwelling unit or converted to an accessory dwelling unit, the local agency shall not require that those offstreet parking spaces be replaced." AB 1170, Stats. 2025, Ch. 67, added uncovered spaces effective January 1, 2026. There is no transit-distance test in that sentence and no attached-garage condition. Conversion ADUs are also among the categories on which Government Code §66322(a) says a local agency "shall not impose any parking standards."

One qualifier belongs next to that rule rather than after it. The City of San Diego's own ADU page lists a Beach Impact area exception outside transit priority zones, requiring one replacement space. That appears to conflict with §66314(d)(11), so a coastal San Diego parcel should confirm the point with Development Services before the drawings assume either answer. The City also notes that if a conversion leaves the driveway less than 18 feet from the sidewalk, the driveway must be closed.

Owner-occupancy is the second one. Government Code §66315 forbids a local agency from imposing an owner-occupant requirement on an ADU. What the agency may require is that the unit be rented for terms of 30 days or longer, which rules out a short-term rental play. JADUs work differently: under Government Code §66333, a JADU that shares sanitation facilities with the primary structure carries an owner-occupancy requirement, and one with separate sanitation facilities does not.

A demolition permit for a detached garage being replaced by an ADU has to be reviewed with the ADU application and issued at the same time, and no demolition notice or placard may be required unless the property sits in an architecturally and historically significant historic district. That is Government Code §66314(e) and (f).

ADU or JADU, and what the permit package has to show

The garage's location decides the legal path before any finish is chosen. A JADU must be "constructed within the walls of the proposed or existing single-family residence," and Government Code §66333(d) counts an attached garage as part of that residence. So an attached garage can take the JADU path; a detached garage cannot, and follows the full ADU path instead. In the City of San Diego, an ADU runs 150 to 1,200 square feet and a JADU 150 to 500 square feet.

The two products carry different strings. A JADU needs an efficiency kitchen, described in statute as "a cooking facility with appliances" plus "a food preparation counter and storage cabinets that are of reasonable size," and a separate entrance; a separate bathroom is not mandated. A recorded deed restriction must prohibit "the sale of the junior accessory dwelling unit separate from the sale of the single-family residence," and it runs with the land. An ADU must have "complete independent living facilities for one or more persons" under Government Code §66313.

Whichever path applies, a building permit is required for every ADU and JADU in the City of San Diego, with no exemptions. The HCD ADU Handbook states that "ADU conversions are subject to all applicable building, health and safety, and fire standards for dwellings," so the converted space has to be brought up to residential dwelling standards and the review covers building, health and safety, fire, and energy code compliance, including emergency egress from sleeping rooms. The permit package includes a Title 24 energy compliance report prepared for that specific property and scope.

A conversion may expand up to 150 square feet beyond the existing structure's dimensions under Government Code §66323(a)(1)(A), solely to accommodate ingress and egress such as a staircase, with setbacks sufficient for fire and safety. Outside the City of San Diego, every one of these state rules still applies, but the submittal process, fee schedule and review queue belong to that city's or the county's building department, and that is the office to confirm the local process with.

On the contract itself, California's Business and Professions Code §7159 governs any home improvement contract over $500, and the statutory deposit language is exact: "THE DOWNPAYMENT MAY NOT EXCEED $1,000 OR 10 PERCENT OF THE CONTRACT PRICE, WHICHEVER IS LESS." Verify any license at cslb.ca.gov before signing. Garage Convert SD is a referral service: we match San Diego County homeowners with licensed independent pros, and the homeowner contracts with and pays the selected pro directly.